The pressure drop also depends on the flow rate and properties of the gas. This leads to equations describing the the flow of a fluid past a collection of particles. Pdf physical insight into the ergun and wen and yu equations for. The ergun equation, the wellestablished relation for the pressure drop over packed beds of spherical particles, can be used to describe the behaviour of a fluidized bed at the minimum fluidization velocity correctly, approximations of the ergun equation give results which are only valid over a limited range of reynolds numbers and are not able. Fluidization velocity an overview sciencedirect topics. Fluidization dynamics has been written for students and engineers who find themselves involved with problems concerning the fluidized state. Properties such as minimum fluidization velocity and void fraction related to limestone. A new package is now available for the deisgn of boilers and steam generators. Single phase incompressible fluid flow pressure drop updated compressible fluid flow through a pipe updated nonnewtonian power law fluid flow through a pipe updated nonnewtonian bingham plastic fluid. Simply select your manager software from the list below and click on download. For the simulations performed horios and berrutis model were applied. Beyond maximum superficial velocity, particles will be carried away by the gas and will leave at the bed exit.
This is to certify that the thesis entitled fluidization in conical bed and. Ergun software is the result of collaboration among researchers in the field of fluidization on one hand and industrial demand on the other hand. Freeboard region, fast fluidization, and circulating solid systems 330 example 1. Fluid software free download fluid top 4 download offers free software downloads for windows, mac, ios and android computers and mobile devices. Particles are important products of chemical process industries spanning the basic and specialty chemicals, agricultural products, pharmaceuticals, paints, dyestuffs and pigments, cement, ceramics, and electronic materials. Come to visit the famous napoleon iiis summer palace at the heart of the city. The ergun equation provides a good description for the relationship of the pressure drop with the flow rate and the gas properties. You should have received a copy of the gnu general public license along with openfoam. Ergun cfb is designed in a simple click and go environment. Pressure drop along a packed bed reactor the above always applies, especially for multiple reactions.
Flow through a packed bed can be described by the ergun equation. As a result, it is to some extent unpredictable and nonuniform. Erguns equation flow through packed beds and fluidized beds r shankar subramanian chemical engineering operations commonly involve the use of packed. Fluidization is an engineering unit operation that occurs when a fluid. The zinc sulphide roasting process simulator under ergun environment needs ergun bfb pack to be installed.
Download limit exceeded you have exceeded your daily download allowance. Different items, composing a fluid bed, canbe designed and studied separately. Their experimental results were compared with the computed values from available fluidization mathematical models such. Research participation program, sponsored by the u. Modeling, design and expert analysis of bubbling fluid beds and their peripherals. Based on a slit model, a pellet scale model has been developed for calculation of drag force imposed on trilobe catalyst particles in a packed bed reactor.
Minimum and full fluidization velocity for alumina used in. Estimated equations for water flow through packed bed of multi size particles mohammed nsaif abbass. Freeboard heat exchange 334 problems 334 references 335 chapter 14 the rtd and size distribution of solids in fluidized beds 337. Pdf effect of bed height, bed diameter and particle. University of groningen particle transport in fluidized. The ergun equation, contd usually, the ergun equation is rewritten in a simplified form simplified only with regard to writing. According to erguns equation, pressure drop over bed height was mainly affected by a. Erguns equation flow through packed beds and fluidized. Other minimum fluidization correlations exist, but eq. Modeling, design and expert analysis of fluidized bed systems. Ergun equation results were far away from the experimental data and the.
To better understand fluidization of a particle bed, it is necessary to determine what range of flow rates allow fluidization, and also, what flow rates will begin to carry the particles out the top of the particle chamber. Handbook of fluidization and fluidparticle systems. The ergun software uses the latest data processing technology and computer science tools. Completely revised and updated, it is essentially a new book. The prediction of v mf by erguns equation for pressure drop. Ergun 1952, using a extensive set of experimental data covering a wide range of particle size and shapes, presented a general equation to calculate the pressure drop across a packed bed for all flow conditions laminar to turbulent. Ergun proposed a single equation valid for laminar and turbulent flow this from che 309 at king saud university. Particle, fluidization grids, bedexpansion, tdh, cyclone, transfer, reaction, expert modeling, gassolid data bank, video show and slide shows buttons beside. The minimum fluidization velocities of a bed in the same size region were determined from a plot of pressure drops vs. Applying the ergun equation to the degradation of a. At this point, bubbles of gas form and rise through the bed. The determination of these critical values and the nature of the transition is of interest in connection with the development of fluidization technology in many branches of industry, and also in connection with certain other.
This volume, fluidization, solids handling, and processing, is the first of a series of volumes on particle technology. For pbr, we often write the design equations in terms of catalyst weight rather than reactor length. Friction factor as a function of reynolds number for a packed bed of particles. Smaller or lighter particles tend to experience smooth fluidization. In the fixed bed regime the total pressure drop can be calculated by erguns eqn as. Introduction gassolid fluidization is the phenomenon whereby a bed of. Robert k niven and others published physical insight into the ergun and wen and yu equations for fluid flow in packed and fluidized beds. The evaluation of the ergun simulations by means of the experiments.
The program is mainly focused on the use of solid fuels like. One needs some type of solid separator after the furnace. Pdf physical insight into the ergun and wen and yu. Symbols are data from experiments, the dashed line is the carmankozney equation, and ergun s correlation is represented by the solid line. Fluidization and fluidparticle systems frederick a. The cfd software was applied to obtain numerical solutions. Erguns equation best correlated the experimental data abstract the aim of this work was the experimental investigation of the particle friction factor for air flow through a packed bed of particles at ambient and elevated temperatures. Effects of pressure drop and superficial velocity on the bubbling.
However, industries can ask for a version adapted to their own process. The experiments were performed by measuring the pressure. You can also access all of the teaching files from our public dropbox. To calculate the pressure drop in a given reactor, the following equation may be deduced. Fluidization of a bed of solid particles springerlink. The drag coefficient for single gas phase flow in a porous media has been calculated by cfd simulation and the results compared to the ergun equation. High velocity causes a large fraction of the sand and ash to become entrained with the flue gas stream monazam and shadle, 2004. By comparing the pressure drop given by the ergun equation to the pressure drop for minimum fluidization, you can calculate the superficial velocity necessary for fluidization. Fluid gives any webapp a home on your mac os x desktop complete with dock icon, standard menu bar, logical separation from your other web. This reference details particle characterization, dynamics, manufacturing, handling, and processing for the employment of multiphase reactors, as well as procedures in reactor scaleup and design for applications in the. The frictional force can be expressed in terms of a friction factor. General equation for pressure drop through a packed bed. At minimum fluidization, pressure drop across bed is balanced by effective weight of the particle.
P is equal to the bed weight per unit crosssectional area, and the particle sphericity. The program is designed to minimize the time needed for a design study. When the gas velocities increase beyond the minimum fluidization velocity, bubbles can form. The version proposed to industries and universities is the full package as presented on this site. We used the ergun equation on the packed bed page to describe the drag exerted on. As is known, fluidization of a bed of solid particles by liquid or gas filtration takes place for certain critical values of the parameters of the filtration regime. Fluidization, solids handling, and processing 1st edition. Those who know well the fluidization domain would focus rapidly on the main topics and probably do not need any help for the interpretation of the results provided by the program. Spoutfluidized beds help suppress defluidization and agglomeration, enhance heat and mass transfer, facilitate the adjustment of operating parameters, extend the size range of particles the spout is a local high velocity region at the center of the bed where solid. The data preparation sheet is composed of a simple click and type grid where units, notation and descriptions are presented. Shankar subramanian chemical engineering operations commonly involve the use of.
In the cfb combustion process the fluidization velocity is increased past the bubbling regime to the transport regime basu, 2006. The results show that the drag coefficient predicted by ergun equation should be. The types of flow regime that can be established in a fluidized bed depend on the parameters such as superficial gas velocity, particle properties, and bed dimension. Closeup of the fluid bed reactor with diverse rapid input parameters including air leakage, spray water and o. Flow regime prediction in a 3d spouted bed using mfixdem. The ergun software is designed to help the user all along a design or study project. The furnace acts as the riser of a fast fluidized bed basu and fraser, 1991. Physical insight into the ergun and wen and yu equations for fluid flow in packed and fluidized beds article pdf available in chemical engineering science 573. Its aim is to distill from the thousands of studies those particular developments that are pertinent for the engineer concerned with predictive methods, for the.
Experimental and theoretical study of minimum fluidization. Fluidization engineering, second edition, expands on its original scope to encompass these new areas and introduces reactor models specifically for these contacting regimes. Ergun boilers design package is dedicated to the design of combustors and boilers. Using fluid, you can create ssbs to run each of your favorite webapps as a separate cocoa desktop application. If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. If you cant find what you are looking for, please email us. The ergun equation, derived by the turkish chemical engineer sabri ergun in 1952, expresses the friction factor in a packed column as a function of the modified reynolds number. It presents an analysis that focuses directly on the problem of predicting the fluid dynamic behaviour of a proposed fluidized system for which empirical data is. The results from ergun equation using similar conditions have been represented in the curves for the sake of comparison. Abstract the flow of dry particulate materials is influenced by many variables, including particle shape and size distribution, density, and composition.
We provide teaching versions of our software, tutorials to help you get started, and lots of different data sets for you to analyse and learn from. Additional drag models for the twophaseeulerfoam solver. Ergun software is an interactive computer program for design, study and modeling of bubbling and circulating fluidized beds and their peripherals. Download excel spreadsheet to calculate ergun equation. The point at which this occurs depends on the particle size and density.
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